SST data are especially useful for identifying the onset of El Niño and La Niña cycles. During El Niño, temperatures in the Pacific near the equator are warmer than normal. During La Niña, the same area experiences colder than normal ocean temperatures. These cycles are caused by multiyear shifts in pressure and wind speeds, and affect ocean circulation, global weather patterns, and marine ecosystems.

The Earth emits radiation in both the infrared and microwave wavelengths, and the extent of these wavelengths varies with the temperature of the ocean. Satellite sensors measure these varied temperature bands from space to calculate sea surface temperature.